Silver is effective at killing many types of bacteria, and, as silver attacks many bacterial processes at once, resistance is unlikely to develop. However, too much silver can damage human cells and prevent healing. This can be a particular problem with wound dressings impregnated with traditional silver nitrate that release large amounts of silver into the wound. Silver nanoparticles are a step forward, presenting silver to wounds at lower concentrations, helping to protect tissue while retaining strong antibacterial activity.
Dr Zlatko Kopecki and colleagues at the University of South Australia (UniSA) and Flinders University, have gone a step further, recently developing bandages that release silver nanoparticles into a wound only as they are needed. This bandage is based on a biocompatible hydrogel containing pores that hold the tiny silver nanoparticles. Our facilities at UniSA provided scanning electron microscopy (SEM) for this research.
Infected wounds are more alkaline (higher pH) than healthy wounds and typically also have a higher temperature. The responsive hydrogel developed by the team changes its structure as temperature and pH increase during bacterial infection to release the silver nanoparticles only into infected areas of the wound. When tested on Staphlococcus aureus-infected wounds, the hydrogel bandages cleared the infection effectively and promoted wound healing.
This combination of targeted release, antibacterial action and improved wound-healing in a single platform could facilitate better treatment for those suffering wounds caused by burns, trauma, surgery or skin disorders and all wounds that are prone to serious infection.
H. Haidari et at., ACS Applied Material Interfaces 2022
DOI: 10.1021/acsami.2c15659
Scanning electron micrograph of the hydrogel in the bandages
December 1, 2023
